Container closures or caps of the reusable type are utilized on a wide variety of products. Typical products include beverages, vitamins, condiments and the like. Such caps, whether made of plastic or metal, generally are provided with a lining in the form of coated aluminum foil membranes, plastic-coated paper or other suitable material.
In assembling a liner into a cap or closure for containers, machines generally are employed which feed the inverted caps sequentially to an assemblying station. A strip of lining material is also fed to the assemblying station and is positioned over the inverted caps where the liners are punched from the strip of lining material and are assembled into the caps. The movement of the caps and lining material to the assembly station, along with the movement of the punch or other assemblying mechanisms generally are controlled by a mechanically interlocked machine involving large numbers of cams, gears and the like. Because of the complex mechanical interraction of parts which are required for the operating sequence, relatively large electric motors also are required to power such machines.
The nature of most cap-lining machines which currently are used also is such that if a change from one cap size or diameter to another is desired, significant modifications must be made to the machine. This requires skilled mechanics and results in considerable machine "down-time" to effect the changeover from one size of caps to another. In many installations, where large numbers of caps of different sizes are manufactured and lined, it is not uncommon to have different machines set up to handle different sized caps, even though such machines frequently sit idle for long periods of time between the times caps of the particular size for which a machine has been set up are to be lined. In addition, because of the substantial mechanical complexity of most cap-lining machines, many opportunities for mechanical failure and the wearing out of parts exist. Consequently, it also has been common practice to provide idle backup machines for high production facilities to prevent the interruption of production whenever machines require maintenance, which is often.
In many cap-lining machines of the prior art, if, for some reason, the cap-feeding mechanism fails to sequentially feed caps, it was possible for the punch and insert mechanism to attempt to insert a second liner into a cap at the liner inserting station of the machine. Because of the close tolerances involved, this results in a jamming of the punch and frequently expensive mechanical failure of gears, cams and levers in the machine. In addition, if the web of liner fails to advance in synchronization with the cap feeding operation, it is possible in many prior art machines to continue operation without the insertion of liners into some caps. Unless a provision is made for detecting (either automatically or manually) the presence or absence of liners in caps coming out of the machine, it is possible to produce large numbers of defective caps which, subsequently, when applied to containers to close them, would result in inadequate seals for the containers on which they are used.
Attempts have been made on some prior art machines to interrupt operation of the machine when an abnormal condition (such as a missing cap) occurs. One such machine is shown in the patent to Belada, U.S. Pat. No. 2,391,381. This patent is directed to a mechanical cap-lining machine with a large number of moving parts and requiring a large electric motor to power it. An electrical sensing switch, however, is used in Belada to detect a missing cap just prior to the punch/insertion stage to stop operation of the paper stock feed whenever a cap is missing in this position. The sensing of a missing cap, however, does not stop the punch or any of the other mechanisms in the operation of the machine. In addition, this machine does not have a structure which permits rapid changeover from one size cap and liner combination to another.
Another machine which operates in a manner similar to Belada is disclosed in the patent to Jenkins, U.S. Pat. No. 2,912,042. The Jenkins machine also is a mechanical machine, including gears, cams and levers for synchronizing the feeding of liner material with the feeding of closures to a closure-liner insertion position. A provision is made for detecting the failure of the machine to present a closure to the insertion station to cause temporary interruption of the feed of liner material to the liner insertion punch. No other provisions for interrupting operation in response to other types of failure, however, are present and the machine is subject to the same changeover limitations or disadvantages mentioned above in conjunction with the Belada patent.
It is desirable to provide a cap-lining or closure-lining machine which is not subject to the disadvantages of the prior art mentioned above. Specifically, it is desirable to provide a cap-lining machine which minimizes the complicated mechanical interconnections of the various stages of conventional cap-lining machines. It further is desirable to provide a cap-lining machine which readily may be changed over to handle caps of different sizes with a minimum amount of down-time required to effect such a changeover.